Calories from ___... what ratio do you shoot for?

I'm trying to track my calories in Fit Day, and it gives you a pie chart of where your calories are coming from: fat, carbs, and protein (and alcohol if applicable). I try to get the protein slice as big as I can, as it's the slow-burn kind. But I'm curious what others shoot for in terms of percentage. I generally feel I'm doing well to hit 30% of calories from protein.